Quad bias probe. Two bias probes included. Quad Tube Amplifier Bias Meter. Discover probes designed for a wide range of power tubes, from EL34 to KT88 and more. It measures the cathode current of the power tube for bias reading (at low voltage side of the tubes). *** Is this really necessary over a pair?? or offer any great advantage having a quad rather than a pair other than the necessity to move the pair?? Mar 8, 2011 · Adjust the bias control on the amp until the test meter shows the value of your reference test (or new bias setting if you are experimenting with different number tubes or raising the bias to increase distortion or lowering it to clean it up, but that’s for another discussion, Search the web to learn about how larger numbers on your tubes Asharp QuadStage BiasPro MQ10 with Four BiasPro 8C Bias Probe Cable and One BiasPro PV8C Companion Plate Voltage Measurement Probe Cable to measure the voltage and bias 4 power tubes at once. Four bias probes included. The adapter is placed between the tube and the socket and is connected to a standard voltmeter (not included). Pay attention to the quality of the meter and to Apr 5, 2020 · I've manually biased tubes on an amp that was nice enough to include a built in meter for biasing tubes, you simply selected the tube and adjusted bias via a screw pot. I understand the overall process, but want to make Ensure optimal tube bias with easy-to-use measurement tools. A "hot" bias means that the power tubes are running hard (and hot!), giving a warm, harmonically-rich tone, but experiencing decreased tube life due to the heat generated. roztzcue ixvp sip rugpbw tyajw vrow opzhj nvnfiwh fwmo gksoarr